Modular key lock having lever tumblers with bendable portions

ABSTRACT

A key lock which can be produced in modular form with standardized tumblers. The tumblers are levers which have bendable or deformable portions, and are fitted to a particular cut key by inserting the key into the lock and turning it while the tumblers are held against turning in predetermined position. This displaces the bendable portions of the tumblers to new positions corresponding to the respective lift heights of the key which is used to carry out the bending.

United States Patent Parrock 5] Apr. 17, 197 3 [5 MODULAR KEY LOCKHAVING 1,953,535 4/1934 Hurd ..29/445 LEVER TU E WITH BENDABLE 3,208,2489/1965 Twice... ..70/383 3,315,503 4/1967 Schlage ..70/383 Inventor:Joseph J. Pal-rock, Milford, Ohio The Mosler Safe Company, Hamilton,Ohio Filed: Jan. 31, 1972 Appl. No.: 222,153

Assignee:

US. Cl ..70/355, 70/383 Int. Cl. ..E05b 25/00 Field of Search ..70/355,376, 377,

References Cited UNITED STATES PATENTS 3/1932 l-leyer ..70/377 X PrimaryExaminerRobert L. Wolfe Attorney-James S. l-light et a].

[ ABSTRACT A key lock which can be produced in modular form withstandardized tumblers. The tumblers are levers which have bendable ordeformable portions, and are fitted to a particular cut key by insertingthe key into the lock and turning it while the tumblers are held againstturning in predetermined position. This displaces the bendable portionsof the tumblers to new positions corresponding to the respective liftheights of the key which is used to carry out the bending.

15 Claims, 7 Drawing Figures PATENTEU APR SHEET 1 [IF 2 MODULAR KEY LOCKHAVING LEVER TUMBLERS WITH BENDABLE PORTIONS This invention relates tokey locks of the lever tumbler type, that is, the type which includes atleast one set of tumblers in the form of levers mounted for swingingmovement about an axis, in response to the turning of a cut key. Theinvention is particularly concerned with a lock of the type describedwhich can be produced in a standard or modular condition, not fitted toany particular key at the time it is assembled, and which thereafter canbe set to any of a very large number of keys by the initial turning ofany key which is selected.

The conventional key lock of the lever tumbler type includes a pluralityof tumblers which are mounted for rotation about a fixed post in thelock case, with each tumbler having a gate or open slot at one end. Thelevers are turned about the post by a corresponding key to angularpositions such that the gates of the respective tumblers are disposed inalignment to receive the bolt, and thereby permit the latter to bewithdrawn. Springs urge the tumblers toward a stop and, when no key actson the tumblers, hold them against the stop. In this rest" mode, thestop positions the tumblers so that their gates are disaligned withrespect to the bolt, and the tumblers thereby block withdrawal 'of thebolt. The

gates are formed at different positions on the different I tumblers, sothat each tumbler must be turned a different amount by the key in orderto align its gate with the bolt. Thus, the different lifts of the keyturn the different tumblers through different angles about the post,sufficiently to bring all of the gates into bolt alignment.

To coordinate each conventional lock to the particular key with which itis to be used, the lock must be assembled with tumblers having gates atsuch positions that they will be aligned by the respective lifts of thekey to be used. The keys lifts are cut according to a random schedule,and the lifts differ from key to key and on each individual key. Thus,each key requires a different specific set of tumblers to respondproperly and be aligned by it. Literally, each lock has heretoforenecessarily been built to fit one and only one key. Obviously, this hasnecessitated close and painstaking correlation between key and lockduring lock assembly.

As can be appreciated, it is desirable to simplify lock construction toenable locks to be produced in a standardized form, without the previousrequirement of individualized key-tumbler correlation, and such that asproduced, all locks would be substantially identical to one another andcould be fitted to different keys after assembly.

The desirability of such standardization is especially great in locksfor safety deposit vaults, wherein hundreds or even thousands of locksare used, each of which requires two different keys, a bank or guard keyand a customer key.

it has been a principal objective of this invention to provide a lockconstruction such that the lock manufacturer can build standardizedlocks with each tumbler identical, and which can thereafter be set orfitted to any of many different keys, merely by inserting a particularkey in the lock and turning it.

The invention centers around a lever tumbler which can yield by bendingin response to the initial or setting operation of the key with which itis to be used. The

bendable part of the new tumbler is a key-engaging portion. Prior tobending of this portion, it coacts with a stop against which the tumblerrests in one position; in bending, it is moved so that the tumblerthereafter rests in a different position. The surface on the tumblerwhich engages the stop prior to bending can be considered to be a firstactive stop-engaging surface. After the bending, a second stop-engagingsurface becomes active. The lock is constructed of tumblers in theunbent, undeformed condition, and the respective tumblers are fitted tothe corresponding lifts of the particular key by turning the key whichcauses the bendable portions of the tumblers to be bent.

The new tumbler comprises a lever which in assembly is mounted on a postfor rotation around the post in response to turning of the key. At oneend a gate is formed in the tumbler, shaped to receive the bolt when thetumbler is properly aligned, and thereby permit the bolt to beretracted.

The key-engaging portion of the tumbler is narrow or is connected to thetumbler by a narrow neck which can yield in bending. This portion isdisposed to be bent when the key is first turned while the tumbler isheld against turning. As manufactured, the key-engaging portion is in aposition such that it will be engaged by the key, regardless of thedepth of the particular key lift. Prior to first usage, the firststop-engaging surface of the tumbler rests, under the influence of abias spring, against stop means in the case. The first stop-engagingsurface positions the tumbler so that its gate is either aligned withthe bolt, or is in a predetermined position with respect to the bolt. Byturning the key while the tumbler is held against movement, thekeyengaging portion is bent to a new position with respect to theremainder of the tumbler, the amount of the bending depending upon andvarying with the depth of the particular lift of the key.

In the new or bent position, the first stop-engaging surface is renderedinactive or is displaced from its original position, and does not restagainst the stop means at the same point. The second stop-engagingsurface becomes the active stop surface, and is urged by the bias springto a rest position in which it resides against the stop means, at anangular position such that the tumbler gate is disaligned with the bolt.Thereafter, to align the gate of that tumbler with the bolt, the properkey must be used, to bear on the key edge of the tumbler and turn thetumbler against the spring bias, to bring the gate into the properposition.

In a preferred embodiment, the key-engaging portion of the tumblerprovides the first stop-engaging surface, which coacts with a first stopin the lock case. When the bendable portion is bent by the key, thisfirst stopsecond stop-engaging surface on an unbent part of was made Itis recognized that other locks having bendable tumbler portions areknown. Schlage US. Pat. No. 3,315,503 shows a construction cylinder lockhaving tumblers in the form of pins which can be bent to shorten theireffective length and thereby change them from fitting a first key, tofit a second key. A specially fitted first key is required to open thelock, prior to patent contains no disclosure concerning lever tumblers.

In Hurd US. Pat. No. 1,953,535, pin tumblers are shown which can bebroken along predetermined lines so as to fit the lock to an individualkey. Again the number of possible keys to which the lock can be fittedis relatively limited.

In Nawn, U.S. Pat. No. 2,025,293, a sliding tumbler for a cylinder lockis shown which has an end portion that is bent or arched. This is saidto accommodate the irregularlyserrated edge of a key, so that thetumbler will glide readily over horizontalledges parallel to the keystransverse edge. The purpose is not to fit the lock to any of a largenumber of keys, but rather to render the lock operable by duplicate keyswhich differ only minutely.- I

In US. Pat. No. 1,840,323 there is disclosed a cylinder lock havingsliding tumblers in which the tumblers are bendable. However, thebendable portions cannot be bent by use of the key, but must becompressed against the key by means of a special assembly tool; US. Pat.No. 2,058,853 is a further variant on that concept.

Quillen US. Pat. No. 3,255,620 shows a lock having a tumbler made from amaterial which can be bent, but the tumbler is resilient or elastic, andreturns to its neutral position when freed. The bending is reversible,in contrast to the present lock, in which the tumbler is permanentlydeformed by the bending in order to retain its fit to the correspondingkey.

As an example of its utility, the lock embodying the invention isespecially useful in two key locks of the type used with safety depositboxes. Since the invention in that environment, it is describedhereinafter primarily in relation to safety deposit box locks, but itshould be understood that the invention is not limited to that use.

Safety deposit box locks commonly require use of two different keys,before the box can be opened. One key, which is retained by the bank orthe guard, is used first and aligns one set of tumblers. A second key,which is retained by the particular customer, must then be used tooperate another set of tumblers. All the tumblers of both sets must bein their proper alignments before the bolt can be withdrawn. Thisprevents opening of the box by either the bank alone, or the customeralone.

Ordinarily all the boxes in a given installation will be fitted to thesame guard key, so that the guard need only carry one key to operate theguard tumblers of all the locks. Different banks of course havedifierent guard keys. Each customers key is different, so that eachcustomers key can open only one single lock.

The fact that two keys are used with two sets of tumblers has causedcomplications in the assembly of safety deposit locks. Heretofore, inorder to provide locks to fill a specific banks requirements, themanufacturer has had to assemble all the locks to the particular banksguard key, and each lock to a different customers key. The locks couldbe assembled only after the specific banks order was placed; this wasnecessary to match the guard tumblers to the particular banks guard key.This caused substantial delay in delivery, since renewal lock orders hadto include the necessary guard key information so that the tumblerscould be matched at the factory assembly operation. It was virtuallyimpossible to assemble locks for inventory in advance of order, sincethe guard key shape was not known in advance.

The tumblers of this invention can usefully be employed to comprise eachtumbler of the set which is operated by the guard key. More generally,tumblers in accordance with the invention are useful in either or bothsets of tumblers, that is, as either the guard tumblers or the customertumblers or both in a safety deposit lock, or they can be used in singlekey locks. The new tumblers may comprise a portion, less than all, ofany tumbler set in which they are used.

The invention can best be further described by reference to theaccompanying drawings in which:

FIG. 1 is a fragmentary perspective view of a portion of a multiplesafety deposit box installation and shows a typical environment of apreferred form of safety deposit lock in accordance with the invention;

FIG. 2 is a horizontal section through a preferred form of safetydeposit box lock and is taken on line 2- 2 of FIG. 1;

FIG. 3 is a plan of a guard tumbler including the features of theinvention, as used in the preferred embodiment;

FIG. 4 is a vertical section taken on line 4-4 of FIG. 2 and shows aguard tumbler prior to bending, with the bolt retracted and thebit'engagecl in the gates of the guard and customer tumblers;

FIG. 5 is a view similar to FIG. 4, but shows the guard deposit boxtype. For that reason, this preferred embodiment of the invention isdescribed with relation to such locks, although it should be understoodthat th invention is not limited to two key locks.

The safety deposit box installation shown in FIG. 1

includes a plurality of lockable doors, each designated lock shown forpurposes of illustration, the nose 14 receives the so-called customer orlocking key, and nose 15 receives the guard key, but this order couldreversed.

In keeping with the usual practice, a guard key, which is retained bythe bank or guard, will operate guard tumblers of the locks on all ofthe doors 10, and each box requires its own individualized customer keyto operate customer or locking tumblers. Both the customer and guardtumblers must be aligned before the bolt can be withdrawn.

FIGS. 2 and 4-6 show the arrangement of the guard and customer tumblerswithin a lock. The lock 18 is fastened by machine screws 19 to theinside surface of the box door 10, and is contained within a two parthousing which includes a case 20 and a lid or cover plate 21. The lid 21is disposed facially against the inside surface of the door 10. The twonoses 14 and 15 are mounted to the lid, and project into cooperatingapertures formed in the door 10, substantially to the surface of thelock door, and receive the customer and guard keys respectively.

A key post 24 (which receives the customer key) and a key post 25 (whichreceives the guard key) are rotatably supported at their opposite endsbetween the noses l4 and 15, and apertures 26, 26 in the bottom of thecase 20. Each key post 24, 25 has an elongated shank portion 28, asmaller diameter neck 29 which is seated in the case aperture 26, and anenlarged stepped head 30 which is carried and retained by a flange orrim in the respective nose 14 or 15. Thus each key post 24 and 25 isrotatable within its respective journals, but cannot shift axially. Asshown in FIGS. 46, each key post 24 and 25 is slotted along its length,as at 32, to receive the respective key. The customer and guard keys aredesignated at 34 and 35 respectively in FIGS. 4 and 5, in which they areshown inserted within their respective key posts.

A fixed post or pivot 38 projects from the inner or back surface of thelock case toward lid 21 (see FIG. 2), and a screw 39 which passesthrough the lid is threaded into this post 38 to hold the lid and casein closed relation prior to fitting to the particular door 10. As willbe seen, this post 38 conveniently serves as the pivot for each of thetwo sets of tumblers to be described.

Lock case 20 has an endwise opening through which the bolt 41 extends.The bolt includes a bolt pin or racking pin at 42, and is movablebetween a retracted position (shown in FIG. 4) and an extended position(shown in FIG. 2). The bolt contains a slot 43 indicated by the dottedlines in FIGS. 4-6. Post 38 extends through an elongated portion 48 ofslot 43, and supports and guides the bolt for sliding movement betweenthe retracted and extended positions. Bolt slot 43 also includes aportion 44 (see FIG. 5) which is engaged by and cooperates with a boltthrower in the form of a key bit or foot 45 that is mounted at the innerend of a customer key post 24. A stub or pin 46 on the lock case bottomlimits the angular rotation of the dog in the clockwise direction, seeFIGS. 4 and 5, and hence the retracted position of the bolt. The end ofslot portion 48 fixes the extended position of the bolt.

The lock includes-a set of guard tumblers, which are operated by theguard key, and a set of customer or locking tumblers which are operatedby the customer key. Either or both of these sets of tumblers may have abendable stop feature in accordance with the invention; in theembodiment illustrated, this feature is used on the guard tumblers only,and the customer tumblers are conventional. v

The customer tumblers are designated at 49 and the new tumblers, used asthe guard tumblers are designated at 50. In the particular lock shown,there are seven tumblers of each type, and they are arranged alternatelywith one another within the case, but it is pointed out that neither ofthe number nor the order of arrangement is critical. All of the tumblers49 and 50 are levers which are pivotable about post 38.

As shown in FIG. 2, the tumblers of the different sets are interleavedwith one another on post 38; a customer tumbler 49 is adjacent the lid,then a guard tumbler, then a second customer tumbler, etc.

Only a single guard tumbler and a single customer tumbler are shown inFIGS. 4-6, to simplify those drawings, but it will be apparent that theother tumblers of the respective set can be similar in outline form,except that they vary from tumbler to tumbler in respect to gateposition, and hence, position of alignment.

The customer tumbler 49 is suitably in the form of a thin flat memberhaving an aperture by which it is journalled for rotation about post 38.At one end the tumbler includes a gate 53 shaped toreceive the rackingpin 42 of the bolt when properly aligned therewith. A bias spring 54urges the customer tumbler in the counterclockwise direction around post38, toward a rest position in which a stop-engaging surface 55 bearsagainst and is arrested by the side of the customer key post 24 (seeFIG. 6). In the locked condition, spring 54 holds the customer tumbler49 in this position with the stop-engaging surface 55 against thecustomer key post; as shown in FIG. 6, in this position the gate 53 ofthe customer tumbler 59 is disaligned with respect to the racking pin42. Thus the customer tumbler will block withdrawal of the bolt, sincethe pin 42 would bump against the end surface 56 of the tumbler.

When the customer key 34 is inserted in the slot 32 in the customer keypost 24 and turned clockwise, the particular lift of the key that ispositioned under the respective customer tumbler bears upon akey-engaging surface 57 of the tumbler and turns the tumbler clockwisearound post 38 (compare FIGS. 6 and 4). As this occurs, it can be seenthat the gate 53 is swung upward to a position such that the gate isproperly aligned to receive the bolt as shown in FIG. 4. (Thisillustrates the need for proper correlation of tumbler and key; if animproper key were used, the tumbler would be turned by the lift of thekey an amount which does not move the gate into alignment to receive thebolt.)

The guard tumbler 50 having the bendable feature in accordance with theinvention is shown in plan form in FIG. 3. The lock is assembled withall of its guard tumblers in the unbent condition, shown in this figure.Like the customer tumbler 49, this tumbler is flat and relatively thin,and is mounted for rotation on post 38, which passes through an aperture60 in the tumbler. The tumbler has a gate 61 formed in its end and isbiased in clockwise direction about post 38 by a bias spring 62.

In contrast to the customer tumbler, the guard tumbler has twostop-engaging surfaces, a first or initially active stopaengagingsurface 63 and a second or subsequently active stop-engaging surface 64.These surfaces 63 and 64 coact with first and second stops whichcomprise, respectively, the guard and customer key posts and 24. Thesecond stop-engaging surface 64 can correspond generally to thestop-engaging surface 55 of the customer tumbler, which bears on theopposite of the customer key post 24 (see FIG. 6).

The guard tumbler has a guard key-engaging portion 65 which is presentedon an elongated arm 66 that is bendable with respect to the remainder ofthe customer tumbler. This arm 66 also presents the first stop-engagingsurface 63. Specifically, the arm 66 is connected to the tumbler by anarrow neck 67, which can be bent so that the key-engaging portion 65,and the first stop-engaging surface 63, assume a different position withrespect to the gate and the second stop-engaging surface 64 (compareFIG. 5, in which arm 66 has been bent, with FIG. 4, which shows arm 66in the unbent or as manufactured position).

Prior to bending'the tumbler to fit the key, the first stop-engagingsurface 63 is the active stop, that is, the one which controls thetumbler rest position. The bias spring 62 urges the tumbler clockwisearound post 38 to a position which stop surface 63 rests against theguard key post 25 (see FIG. 4). It can be seen that in this position thesecond stop-engaging surface 64 is in active, that is, it is spaced fromand does not contact the second stop, i.e., the customer key post 24. Inthis position the gate 61 of the guard tumbler is disposed in alignmentto receive the racking pin 42. Thus, prior to setting to a particularguard key, use of the customer key alone will suffice to retract thebolt, since the guard tumblers are already aligned. When the guard keyis inserted in its slot 32 in the guard key post 25, and the key turned,the liftof the key-regardless of its height-will come into engagementwith the key-engaging portion portion 65 and will stress that portionoutwardly thereby causing the neck 67 to bend and stop surface 63 to bemoved. In this embodiment the key bears on the first stop-engagingsurface 63, and the key post 25 acts as the first stop. However, it ispointed out that the stop surface could be spaced from the key edge andcould coact with a stop separate from the key post.

To permit the necessary bending, the material of which the tumbler ismade should not be resilient to the stress placed on it, but should bepermanently deformed by it so that the key displaces the key-engagingportion. 65 and the first stop surface 63 to a new position (asindicated in FIG. 6) which will substantially be retained when the keyis withdrawn. A suitable material is copper alloy No. 342, a high leadedbrass with respect to the racking pin 42. Thereafter, in order tooperate the lock, the same guard key must be used,

in order to engage the key-engaging portion 65 of the tumbler and causethe tumbler to be swung about post 38 in the counterclockwise directionan amount corresponding to the amount of the bend and thereby bring thegate into alignment.

In the past, the guard tumblers on safety deposit locks have had to beassembled to match the particular guard key of the installation in whichthey are to be used. This face prevented inventorying of completed locksby the manufacturer, since there was no advance knowledge of the shapeof the particular 7 guard key which the guard tumblers would have tofit. The ordering bank had to supply that information, and only thencould the locks be assembled.

The present invention overcomes that problem. The particular guard keycan be fitted to pre-assembled locks, taken from inventory.

The customer tumblers must of course be matched to unique customers keysbut since these are random and not specified by the bank, these tumblerscan be assembled in advance as well. Thus, locks having tumblersindividualized to customers keys andmodularized as to guard keys can beassembled andheld in inventory awaiting fitting to the particular banksguard key upon receipt of the order. Once the nature of the guard key isknown, the locks can be fitted to that key, merely by the initial use ofthe guard key.

To set the lock to a particular guard key, the customer key is firstinserted andtumed to withdraw the bolt. This can be done,since prior tobending the guard tumbler gates are held aligned to receive the bolt.The guard key is then inserted in a horizontal position (with referenceto FIG. 4) and-turned counterclockwise 90, its limits of motion beingdetermined by two stops 70 and 71 in the lock case-The racking pin onthe. bolt, engaging in the gates, takes the reaction force of thebending. In this connection, it is desirable although not necessary,that the guard key gates have a slight lead or taper as designated at 72which will air;- commodate slight differences in the yieldability orelasticity of the neck portion' 67 which might cause a small amount ofspring back or overbending, depending on the exact grain structure ofthe tumbler material. When thereafter the bolt is retracted, the rackingpin can cam the tumbler, within a slight range of movement, sufficientlyto bring it in alignment. When the guard and customer keys are bothwithdrawn, the bolt will be extended and all tumblers scrambled.

It should be noted that, instead of using the bolt to hold the tumblersduring this bending step, a pin (insertable perpendicularly throughapertures in the tumblers) or a clamp could be employed to take thereaction force, and thereby hold the tumbler during bending. Use of thebolt for this purpose, therefore, is convenient but not necessary. It isalso noted that, in order to compensate for springback in bending, it iswithin the scope of the inventionto hold each tumbler at a predeterminedfirst position at which its gate is not necessarily aligned to receivethe bolt, .but such that,

after bending and springback, its gate will thereafter be. correctlyaligned, upon subsequent use of the key, to

(Turning the customer key tends to withdraw the bolt, and this can bedone only if the guard tumblers have already been aligned, else theywill block the full rotation of the customer key.) With the guardtumblers aligned, insertion and rotation of the proper customer key 34operates on the customer tumblers to bring them in alignment and also tocause the foot or bit 45 to engage the side of the bolt slot 44 andwithdraw the bolt.

The new tumblers may be employed as less than all of the guard orcustomer tumblers. In other words, not all of the tumblers need be ofthe deformable type, so long as at least one of them is. In this case,however, the number of different keys to which the new tumblers can beset is much more limited.

As previously stated, an advantage accrues even if the new tumblers areused just for the guard tumblers, since this enables locks havingindividualized customer keys but standardized guard tumblers, to bebuilt for inventory, awaiting fitting to the guard keys. However, eventhe need to correlate customer keys and customer tumblers can beobviated by utilizing customer tumblers in accordance with theinvention.

In the embodiment just described, the new tumbler has first and secondstop-engaging surfaces which are distinct and separate from one another,and which become active in one-two sequence. The stop-engaging surfacesmay be combined as described below, as a single surface the position ofwhich is moved by bending. A tumbler of this type is shown in FIG. 7 andmay be used either in a single key lock, or as the customer tumbler in alock of the type described above. In this case the tumbler 74 has asingle key-engaging portion, designated by 75. This comprises a bendableweb or bridge, with an aperture 76 located adjacent to it in thetumbler. in this case, the portion 75 initially rests against the keypost 24 which acts as a stop, and holds the tumbler gate 77 of thetumbler 74 in alignment to receive the bolt. With the bolt withdrawn andthe bit engaged in the gate 77, operation of the key will deform thebendable portion 75 to the position indicated by the dotted lines inFIG. 7. Thereafter, when the bolt has been extended, this new surfacewill, in the rest position, hold the gate in a scrambled position. Thus,rather than a separate second stop surface which replaces the first, theposition of the stop surface is changed with respect to the gate.

Having described my invention, I claim:

1. In a key lock of the lever tumbler type having spring biased levertumblers with bolt receiving gates at the ends thereof alignable topermit a bolt to be retracted, each tumbler having a key-engagingportion which is acted upon by a key, each tumbler being biased by aspring toward stop means presented in the lock case,

the improvement comprising,

at least one lever tumbler having a bendable key-engaging portiondisposed to be bent by initial rotation of the key in the lock,

stop means against which said bendable portion rests under the bias ofsaid spring prior to bending and which positions the tumbler in apredetermined first position with respect to the bolt, and against whichsaid tumbler rests after bending in a different second positiondependent upon the shape of the key, in which second position the gateis out of alignment with the bolt,

and means for preventing rotation of the tumbler when the key is turnedwhile the tumbler is in the first position. 2. The improvement of claim1 wherein the bendable 5 key-engaging portion comprises an armprojecting from the tumbler which is connected to the tumbler by ayieldable neck.

3. The improvement of claim 1 wherein the bendable portion is ayieldable web adjacent an aperture in the tumbler and which isdeformable by bending relative to said aperture.

4. The improvement of claim 1 wherein the stop means positions thetumbler in the first predetermined position such that the gate is inalignment to receive the bolt.

5. The improvement of claim 1 wherein the stop means includes discretefirst and second stops in the lock case.

6. The improvement of claim 1 wherein the first stop is a key post.

7. In a key lock of the lever tumbler type having spring biased levertumblers with bolt receiving gates at the ends thereof which arealignable to permit a bolt to be retracted, each tumbler having akey-engaging portion which is acted upon by a key, each tumbler beingbiased by a spring toward stop 'means presented in the lock case, i

the improvement comprising,

at least one lever tumbler having a bendable key-engaging portion,

the bendable portion prior to bending presenting a first stop-engagingsurface which is positioned to bends it,

and a second stop-engaging surface on said tumbler that is active onlyafter said bendable portion has been bent by said key, said secondstop-engaging surface than being positioned to be arrested by the stopmeans in the case under the influence of said spring, in a position inwhich said gate is disaligned with respect to the bolt.

8. The improvement of claim 7 wherein the bendable key-engaging portioncomprises an arm projecting from the tumbler which is connected to thetumbler by a neck.

9. The improvement of claim 7 wherein the bendable portion coacts with afirst stop in the lock case prior to bending,

and wherein the second stop-engaging surface is not on the bendableportion of the tumbler, and is so positioned that after the bendableportion has been bent it is engageable in rest position by a second stopin the case which is spaced from the first stop.

10. The improvement of claim 9 wherein the first stop is the key post ofthe key which bends the bendable portion.

11. The improvement of claim 7 wherein the bendable portion, afterbending, becomes the second stopengaging surface.

ing to the shape of the particular key lift whichv 12. A rotatable levertumbler for a key'lock comprisan end portion having a gate formedtherein for receiving a bolt,

means for joumalling said tumbler for rotation,

a key-engaging portion disposed for engagement with a key, saidkey-engaging portion being deformably connected to the remainder of thetumbler so as to be bendable to a new position by said key when thetumbler is held against rotation,

a first stop-engaging surface associated with said keyengaging portionand bendable therewith, said first stop-engaging surface prior tobending being positioned so that it can be arrested by stop means in thecase and when so arrested will position said tumbler in a predeterminedfirst position,

means engageable with the tumbler to prevent it from turning when insaid first predetermined position,

and a second stop-engaging surface on said tumbler, said secondstop-engaging surface positioned so that it can be arrested by said stopmeans to arrest said tumbler in a second position at which the gate isdisaligned with respect to a bolt, after said keyengaging portion hasbeen bent.

13. In a keylock of the lever tumbler type,

a deformable lever tumbler having an end portion with a gate formedtherein for receiving a bolt,

means for joumalling said tumbler for rotation,

a key engaging portion'of said tumbler disposed for engagement with akey, said key-engaging portion being deformably connected to theremainder of the tumbler so as to be bendable to a new position by saidkey when the tumbler is held against rotation, 1

stop means in the case for engaging the tumbler in a rest position underbias of a spring,

the key-engaging portion prior to deformation bearing against the stopmeans and holding the gate in alignment to receive'the bolt,

the key-engaging portion prior to deformation being engageable with thekey to be deformed by the key if the latter is rotated when the bolt isengaged with the tumbler,

the key-engaging portion subsequent to deformation bearing against thestop means after thekey is removed and holding the gate in a position ofdisalignment with the bolt.

14. In a key lock of the lever tumbler type having spring biased levertumblers with a bolt receiving gates at the ends thereof alignable topermit a bolt to be retracted, each tumbler having a key-engagingsurface which is acted upon by a key, each tumbler being biased by aspring toward stop means presented in the lock case,

the improvement wherein at least one of the tumblers has a key-engagingportion that is bendable by initial rotation of the key,

said key-engaging portion prior to bending resting against a stop in thecase and holding the tumbler gate in alignment to receive the bolt,

said tumbler also having a portion that, when the key-engaging portionhas been bent, rests against a stop in the case and holds the gate indisalignment with the bolt. 15. In a two key safety deposit box lock ofthe lever tumbler type having a set of customer tumblers operated by acustomers key and a set of guard tumblers operated by a guard key, thetumblers having bolt receiving gates at the ends thereof which inordinary use must be properly aligned by the respective keys to permit abolt to be retracted, each tumbler having a key-engaging portion whichis acted upon by a key, each tumbler being biased by a spring towardstop means presented in the lock case,

the improvement wherein each guard tumbler has a guard key-engagingportion which is bendable and which is positioned to be bent by theinitial rotation of the guard key,

said guard key-engaging portion prior to bending resting against a guardkey post and holding the tumbler gate in alignment to receive the boltwhen the latter is withdrawn,

said guard tumbler also having a portion that after bending by said keyrests against a customer key post and holds the gate in disalignmentwith the bolt.

1. In a key lock of the lever tumbler type having spring biased levertumblers with bolt receiving gates at the ends thereof alignable topermit a bolt to be retracted, each tumbler having a key-engagingportion which is acted upon by a key, each tumbler being biased by aspring toward stop means presented in the lock case, the improvementcomprising, at least one lever tumbler having a bendable key-engagingportion disposed to be bent by initial rotation of the key in the lock,stop means against which said bendable portion rests under the bias ofsaid spring prior to bending and which positions the tumbler in apredetermined first position with respect to the bolt, and against whichsaid tumbler rests after bending in a different second positiondependent upon the shape of the key, in which second position the gateis out of alignment with the bolt, and means for preventing rotation ofthe tumbler when the key is turned while the tumbler is in the firstposition.
 2. The improvement of claim 1 wherein the bendablekey-engaging portion comprises an arm projecting from the tumbler whichis connected to the tumbler by a yieldable neck.
 3. The improvement ofclaim 1 wherein the bendable portion is a yieldable web adjacent anaperture in the tumbler and which is deformable by bending relative tosaid aperture.
 4. The improvement of claim 1 wherein the stop meanspositions the tumbler in the first predetermined position such that thegate is in aLignment to receive the bolt.
 5. The improvement of claim 1wherein the stop means includes discrete first and second stops in thelock case.
 6. The improvement of claim 1 wherein the first stop is a keypost.
 7. In a key lock of the lever tumbler type having spring biasedlever tumblers with bolt receiving gates at the ends thereof which arealignable to permit a bolt to be retracted, each tumbler having akey-engaging portion which is acted upon by a key, each tumbler beingbiased by a spring toward stop means presented in the lock case, theimprovement comprising, at least one lever tumbler having a bendablekey-engaging portion, the bendable portion prior to bending presenting afirst stop-engaging surface which is positioned to engage and bearrested by said stop means in a position such that the gate is inalignment to receive the bolt, the bendable portion prior to bendingbeing bendable by the key, if the key is turned with the tumbler heldagainst turning, to a new position corresponding to the shape of theparticular key lift which bends it, and a second stop-engaging surfaceon said tumbler that is active only after said bendable portion has beenbent by said key, said second stop-engaging surface than beingpositioned to be arrested by the stop means in the case under theinfluence of said spring, in a position in which said gate is disalignedwith respect to the bolt.
 8. The improvement of claim 7 wherein thebendable key-engaging portion comprises an arm projecting from thetumbler which is connected to the tumbler by a neck.
 9. The improvementof claim 7 wherein the bendable portion coacts with a first stop in thelock case prior to bending, and wherein the second stop-engaging surfaceis not on the bendable portion of the tumbler, and is so positioned thatafter the bendable portion has been bent it is engageable in restposition by a second stop in the case which is spaced from the firststop.
 10. The improvement of claim 9 wherein the first stop is the keypost of the key which bends the bendable portion.
 11. The improvement ofclaim 7 wherein the bendable portion, after bending, becomes the secondstop-engaging surface.
 12. A rotatable lever tumbler for a key lockcomprising, an end portion having a gate formed therein for receiving abolt, means for journalling said tumbler for rotation, a key-engagingportion disposed for engagement with a key, said key-engaging portionbeing deformably connected to the remainder of the tumbler so as to bebendable to a new position by said key when the tumbler is held againstrotation, a first stop-engaging surface associated with saidkey-engaging portion and bendable therewith, said first stop-engagingsurface prior to bending being positioned so that it can be arrested bystop means in the case and when so arrested will position said tumblerin a predetermined first position, means engageable with the tumbler toprevent it from turning when in said first predetermined position, and asecond stop-engaging surface on said tumbler, said second stop-engagingsurface positioned so that it can be arrested by said stop means toarrest said tumbler in a second position at which the gate is disalignedwith respect to a bolt, after said key-engaging portion has been bent.13. In a keylock of the lever tumbler type, a deformable lever tumblerhaving an end portion with a gate formed therein for receiving a bolt,means for journalling said tumbler for rotation, a key-engaging portionof said tumbler disposed for engagement with a key, said key-engagingportion being deformably connected to the remainder of the tumbler so asto be bendable to a new position by said key when the tumbler is heldagainst rotation, stop means in the case for engaging the tumbler in arest position under bias of a spring, the key-engaging portion prior todeformation bearing against the stop means and holding the gate inalignment to Receive the bolt, the key-engaging portion prior todeformation being engageable with the key to be deformed by the key ifthe latter is rotated when the bolt is engaged with the tumbler, thekey-engaging portion subsequent to deformation bearing against the stopmeans after the key is removed and holding the gate in a position ofdisalignment with the bolt.
 14. In a key lock of the lever tumbler typehaving spring biased lever tumblers with a bolt receiving gates at theends thereof alignable to permit a bolt to be retracted, each tumblerhaving a key-engaging surface which is acted upon by a key, each tumblerbeing biased by a spring toward stop means presented in the lock case,the improvement wherein at least one of the tumblers has a key-engagingportion that is bendable by initial rotation of the key, saidkey-engaging portion prior to bending resting against a stop in the caseand holding the tumbler gate in alignment to receive the bolt, saidtumbler also having a portion that, when the key-engaging portion hasbeen bent, rests against a stop in the case and holds the gate indisalignment with the bolt.
 15. In a two key safety deposit box lock ofthe lever tumbler type having a set of customer tumblers operated by acustomer''s key and a set of guard tumblers operated by a guard key, thetumblers having bolt receiving gates at the ends thereof which inordinary use must be properly aligned by the respective keys to permit abolt to be retracted, each tumbler having a key-engaging portion whichis acted upon by a key, each tumbler being biased by a spring towardstop means presented in the lock case, the improvement wherein eachguard tumbler has a guard key-engaging portion which is bendable andwhich is positioned to be bent by the initial rotation of the guard key,said guard key-engaging portion prior to bending resting against a guardkey post and holding the tumbler gate in alignment to receive the boltwhen the latter is withdrawn, said guard tumbler also having a portionthat after bending by said key rests against a customer key post andholds the gate in disalignment with the bolt.